Field of the Invention
The present general inventive concept is directed to a device that provides automated regulation of hot water systems, and a method of utilizing the device to improve performance in hot water systems.
Description of the Related Art
The prior art includes spring loaded valves utilizing thermal expansion of a solid, liquid, or phase change to effect opening or closure of a valve. U.S. Pat. No. 5,816,493 to Pirkle discloses an improved thermally expansible composition that contains silicone rubber and does not require a diaphragm or seal. This concept is insufficient for use in closed systems where the automated valve is installed in-line and in contact with a fluid such as water for extended periods, and will not provide consistent operation over time. Within hot water systems such as showers and sinks, it is known to utilize a valve to direct water flow. It is a common problem that the distance between the hot water heater or hot water source and the location where the user wishes to utilize the hot water causes a delay related to the pipe volume between the source and the user divided by the flow rate. In larger structures or larger diameter pipes, the delay can be substantial. Constant recirculation of hot water within the piping system is commonly utilized to reduce the delay in the delivery of hot water. However, in addition to the delay caused by distance and pipe volume, complex systems can experience resistance to the flow of hot water including gravity. A single hot water source within a system containing many faucets or outlets may not deliver hot water to all parts of the system equally, or sufficiently, to meet demand. Typical installations include the use of a pump, mixing valves, and other manual adjustments to attain delivery to all parts of a piping system in the face of gravity, flow restrictions, and other complicating factors either fixed or dynamic.
Numerous attempts to optimize the delivery of hot water in complex systems have been made. Providing a hot water source nearer to the user is one potential solution, but can be very costly with the additional equipment needed. Providing constant recirculation can reduce the delay as well, but is difficult to regulate in large systems. For example, recirculated water will travel the path of least resistance such that in multistory buildings, the top floors will not receive sufficient recirculation flow. What is needed is an automated valve that can be installed in-line with existing piping systems, that requires no maintenance or adjustment, and can automatically adjust the recirculation flow to ensure the availability of hot water in complex piping systems.
Other attempts to address this problem have been insufficient. For instance U.S. Pat. No. 7,681,804 B2 to Lockhart discloses a temperature-controlled valve that can be inserted above a shower head. This device can be activated by a user to start the flow of water into the shower. The valve will then substantially close after the hot water arrives at the valve. This valve does not obviate the delay in the arrival of the hot water supply. It merely reduces the waste of hot water that would be caused by an inattentive user that is not present at the moment hot water supply arrives. It does allow for a large amount of water to go down the drain while waiting for hot water supply. Numerous other valves have been manufactured and some have been patented, but most require adjustment or settings that make them unsuitable for installation in a piping system behind walls or access panels. What is needed is a valve that provides automated recirculation to ensure that hot water is available soon after requested by a user